MAC Endless Night just came out with the Glamour Daze Collection and is a repromote from the Daphne Guinness Collection which was released in January 2012.

It's a color that is very hard to describe, I would say it's a very light muddy brown with pink iridescent shimmer, MAC says that it's a pale gray pink with iridescent pearl. Well there you go! :-)

The shimmer that you see here in the picture is only visible because I photograph with flash and the shimmer particles really reflect. In real life, the pink iridescence is barely visible!

As far as dupes go, the only color that resembles it in my collection is OPI's Puerto Vallarta Violeta from their Mexico Collection, it's a little more on the lilac/mauve side but shares the same shimmery finish, even if the pearl is not as pink as in MAC Endless Night.

Many of you probably have way more nail polishes than I do and will more easily find a dupe!*edit: Like Mina points out in the comments and many on Blogger seem to agree: Essie Demure Vixen is a possible dupe!

In the bottle, OPI's My Very First Knockwurst from their recent Germany Collection also comes close, but it has a creme finish and no sparkles.

For me personally, OPI's Puerto Vallara Violeta is one of my all-time favorite nail polishes. It's girly without being kitschy, subtle, but with that extra kick of pink, shiny yet subdued. My swatch comparison - unfortunately - doesn't do it justice. I will try to make a better swatch sometime soon!